Maine
Underground Injection Control (UIC) Program
The Underground Injection Control (UIC) Program was established by the federal Safe Drinking Water Act to protect underground sources of drinking water by regulating the subsurface discharge of pollutants through injection wells. In Maine, the Department of Environmental Protection (DEP) administers it, with support from EPA, as part of the subsurface wastewater discharge program of its Bureau of Water Quality. Maine's program dates from 1983, when the Board of Environmental Protection adopted Chapter 543 of DEP's rules.
In a Phase I ESA
ASTM E1527-21 does not name injection well records among its standard record sources. DEP's examples of Class V wells include floor drains that discharge into dry wells, as well as septic systems and leach fields. Three Maine details shape the search.
- Most classes are prohibited. DEP says Class I, II and III wells are prohibited in Maine under its rule 06-096 ch. 543 3(c), and Class IV wells are prohibited other than those used at RCRA or Superfund sites. Most Class V wells are authorized by rule if registered with DEP. Some other Class V wells need a waste discharge license, and two kinds, motor vehicle waste disposal wells and large-capacity cesspools, are prohibited by state and federal law.
- Floor drain changes are reported to DEP. DEP says a business that seals its floor drains, connects them to a holding tank or makes another change must notify DEP in writing, and that the UIC Program requires notice 30 days before closing floor drains in motor vehicle repair areas. DEP uses the information to assess threats to groundwater. For a former repair garage or one of the businesses below, ask DEP for the floor drain notices and any Class V registration.
- DEP names the trades. In explaining high-risk wastewater, DEP's floor drain page lists the potential floor drain pollutants of engine and equipment repair facilities, printers and silk screening operations, photo processors, commercial car and truck washes, dry cleaners, meat packing and food processing facilities, metal fabricators, metal platers and electronic parts manufacturers, pest control and lawn care companies, and drinking water treatment plants.
DEP does not regulate individual or single-family septic systems or grandfathered cesspools under the UIC Program, nor non-residential septic systems or grandfathered cesspools that receive only domestic wastewater and have the capacity to serve fewer than 20 persons per day or dispose of less than 2,000 gallons per day; DEP says local and state officials regulate those under the Maine Subsurface Wastewater Disposal Rules.
Where to look a site up
The pages read link no list of registered Class V wells or floor drain notices. Registrations and notices go to the Underground Injection Control Program, Maine Dept. of Environmental Protection, Bureau of Water Quality, 17 State House Station, Augusta, ME 04333-0017. DEP gives the Division of Water Quality Management at 207-287-7688 for questions.
Getting the file
The pages read do not say where Class V registrations and floor drain notices are kept or how to ask for them. Ask the Division of Water Quality Management, and see DEP's Freedom of Access route on the File Room, Reports and Lists page.
Sources
Maine Department of Environmental Protection pages, read October 13, 2026, no modified date shown: